Yo. Napping is golden for lucid dreaming! Most of my lucid dreams are from naps.
For length, usually do 2 1 hour long naps, for time before nap, varies but i have found out recently that first nap being ~2 hours after waking seems to work best for me personally. The techniques i have success with vary, there have been DILDs, WILDs, DEILDs. As for how long it takes for me to fall asleep, i pay no attention to time because it's not important.